package ocaml-base-compiler
include module type of String
Strings
make n c
is a string of length n
with each index holding the character c
.
init n f
is a string of length n
with index i
holding the character f i
(called in increasing index order).
Return a new string that contains the same bytes as the given byte sequence.
Return a new byte sequence that contains the same bytes as the given string.
get s i
is the character at index i
in s
. This is the same as writing s.[i]
.
Concatenating
Note. The Stdlib.(^)
binary operator concatenates two strings.
concat sep ss
concatenates the list of strings ss
, inserting the separator string sep
between each.
Predicates and comparisons
compare s0 s1
sorts s0
and s1
in lexicographical order. compare
behaves like Stdlib.compare
on strings but may be more efficient.
starts_with
~
prefix s
is true
if and only if s
starts with prefix
.
ends_with suffix s
is true
if and only if s
ends with suffix
.
contains_from s start c
is true
if and only if c
appears in s
after position start
.
rcontains_from s stop c
is true
if and only if c
appears in s
before position stop+1
.
contains s c
is String.contains_from
s 0 c
.
Extracting substrings
sub s pos len
is a string of length len
, containing the substring of s
that starts at position pos
and has length len
.
split_on_char sep s
is the list of all (possibly empty) substrings of s
that are delimited by the character sep
.
The function's result is specified by the following invariants:
- The list is not empty.
- Concatenating its elements using
sep
as a separator returns a string equal to the input (concat (make 1 sep) (split_on_char sep s) = s
). - No string in the result contains the
sep
character.
Transforming
map f s
is the string resulting from applying f
to all the characters of s
in increasing order.
mapi f s
is like map
but the index of the character is also passed to f
.
fold_left f x s
computes f (... (f (f x s.[0]) s.[1]) ...) s.[n-1]
, where n
is the length of the string s
.
fold_right f s x
computes f s.[0] (f s.[1] ( ... (f s.[n-1] x) ...))
, where n
is the length of the string s
.
exists p s
checks if at least one character of s
satisfies the predicate p
.
trim s
is s
without leading and trailing whitespace. Whitespace characters are: ' '
, '\x0C'
(form feed), '\n'
, '\r'
, and '\t'
.
escaped s
is s
with special characters represented by escape sequences, following the lexical conventions of OCaml.
All characters outside the US-ASCII printable range [0x20;0x7E] are escaped, as well as backslash (0x2F) and double-quote (0x22).
The function Scanf.unescaped
is a left inverse of escaped
, i.e. Scanf.unescaped (escaped s) = s
for any string s
(unless escaped s
fails).
uppercase_ascii s
is s
with all lowercase letters translated to uppercase, using the US-ASCII character set.
lowercase_ascii s
is s
with all uppercase letters translated to lowercase, using the US-ASCII character set.
capitalize_ascii s
is s
with the first character set to uppercase, using the US-ASCII character set.
uncapitalize_ascii s
is s
with the first character set to lowercase, using the US-ASCII character set.
Traversing
iter f s
applies function f
in turn to all the characters of s
. It is equivalent to f s.[0]; f s.[1]; ...; f s.[length s - 1]; ()
.
iteri
is like iter
, but the function is also given the corresponding character index.
Searching
index_from s i c
is the index of the first occurrence of c
in s
after position i
.
index_from_opt s i c
is the index of the first occurrence of c
in s
after position i
(if any).
rindex_from s i c
is the index of the last occurrence of c
in s
before position i+1
.
rindex_from_opt s i c
is the index of the last occurrence of c
in s
before position i+1
(if any).
index s c
is String.index_from
s 0 c
.
index_opt s c
is String.index_from_opt
s 0 c
.
rindex s c
is String.rindex_from
s (length s - 1) c
.
rindex_opt s c
is String.rindex_from_opt
s (length s - 1) c
.
Strings and Sequences
to_seq s
is a sequence made of the string's characters in increasing order. In "unsafe-string"
mode, modifications of the string during iteration will be reflected in the sequence.
to_seqi s
is like to_seq
but also tuples the corresponding index.
Deprecated functions
create n
returns a fresh byte sequence of length n
. The sequence is uninitialized and contains arbitrary bytes.
set s n c
modifies byte sequence s
in place, replacing the byte at index n
with c
. You can also write s.[n] <- c
instead of set s n c
.
blit src src_pos dst dst_pos len
copies len
bytes from the string src
, starting at index src_pos
, to byte sequence dst
, starting at character number dst_pos
.
fill s pos len c
modifies byte sequence s
in place, replacing len
bytes by c
, starting at pos
.
Return a copy of the argument, with all lowercase letters translated to uppercase, including accented letters of the ISO Latin-1 (8859-1) character set.
Return a copy of the argument, with all uppercase letters translated to lowercase, including accented letters of the ISO Latin-1 (8859-1) character set.
Return a copy of the argument, with the first character set to uppercase, using the ISO Latin-1 (8859-1) character set..
Return a copy of the argument, with the first character set to lowercase, using the ISO Latin-1 (8859-1) character set.
Binary decoding of integers
The functions in this section binary decode integers from strings.
All following functions raise Invalid_argument
if the characters needed at index i
to decode the integer are not available.
Little-endian (resp. big-endian) encoding means that least (resp. most) significant bytes are stored first. Big-endian is also known as network byte order. Native-endian encoding is either little-endian or big-endian depending on Sys.big_endian
.
32-bit and 64-bit integers are represented by the int32
and int64
types, which can be interpreted either as signed or unsigned numbers.
8-bit and 16-bit integers are represented by the int
type, which has more bits than the binary encoding. These extra bits are sign-extended (or zero-extended) for functions which decode 8-bit or 16-bit integers and represented them with int
values.
get_uint8 b i
is b
's unsigned 8-bit integer starting at character index i
.
get_int8 b i
is b
's signed 8-bit integer starting at character index i
.
get_uint16_ne b i
is b
's native-endian unsigned 16-bit integer starting at character index i
.
get_uint16_be b i
is b
's big-endian unsigned 16-bit integer starting at character index i
.
get_uint16_le b i
is b
's little-endian unsigned 16-bit integer starting at character index i
.
get_int16_ne b i
is b
's native-endian signed 16-bit integer starting at character index i
.
get_int16_be b i
is b
's big-endian signed 16-bit integer starting at character index i
.
get_int16_le b i
is b
's little-endian signed 16-bit integer starting at character index i
.
get_int32_ne b i
is b
's native-endian 32-bit integer starting at character index i
.
get_int32_be b i
is b
's big-endian 32-bit integer starting at character index i
.
get_int32_le b i
is b
's little-endian 32-bit integer starting at character index i
.
get_int64_ne b i
is b
's native-endian 64-bit integer starting at character index i
.
get_int64_be b i
is b
's big-endian 64-bit integer starting at character index i
.
val print : Format.formatter -> t -> unit
val for_all : (char -> bool) -> t -> bool